Buses in Santiago, Chile are a lot like taxis. They don't care about you unless you flag them down for a ride. It doesn't matter if you're waiting at the bus stop. It doesn't matter if there are five of you waiting at a bus stop. The bus isn't stopping unless your hand goes out toward the street to hail it.
I'm embarrassed to admit that I've missed the bus more than once because I was either texting or scrolling through Facebook. Buses don't run 24/7 so you definitely don't want to miss the last one.
My fellow gringos, if you want to be next, don't text.
Like many major cities, you do need to have a metro card (called a BIP! card in Santiago) prior to getting on the bus. It’s a prepaid card that you can buy at any metro station for $1.500 pesos (or just over $2 USD). One bus ride is about $1 USD but the true rate actually fluctuates based on time of day (see price chart in pesos). Transfers between buses and trains range from free to $0.05 USD but regardless if it’s free, you still need to scan your BIP! card. And yes, there is a student discount with a valid student ID which is about a third of the normal price.
Riding tip: There are no electronic signs on the buses that tell you which stop or intersection you are at. You will need to look out the window, ask a fellow passenger or the driver, or use a GPS app on your phone.